Previous lactation devices include manual pumps, hand held battery operated pumps and AC powered devices. Manual lactation pumps require the use of reciprocating hand motion. The breast cup is held in place with one hand and the pump is actuated with either the same hand or, in some applications, both hands. The manual lactation pump can only be used on one breast at a time. The vacuum cycle frequency is controlled by the frequency of pump actuations. The vacuum magnitude is controlled by both a vent setting and the amount of force imparted by the user to each pump stroke. The hand held battery operated pump is activated by an electric switch controlling a small battery operated vacuum pump. These systems can only be used on one breast at a time. The vacuum cycle frequency is manually controlled by the manual release of vacuum through a hand operated release valve. The vacuum magnitude is controlled by the amount of time the pump is activated in conjunction with the amount of time the release valve is left closed.
Heavier duty (120 VAC) lactation pumps are available that can be used on both breasts simultaneously. The vacuum magnitude is adjustable via a vacuum bypass setting. However, the cycle frequency is preset by the manufacturer. Due to the requirement of an AC power source, mobility is severely limited.